The behavior of nonmilitary buildings subjected to blast is considered. Case studies from World War II are described, as well as more recent events from the detonation of large vehicle borne devices in the Middle East, North America, and Europe. Conventional methods for nonseismic design are shown to lead to frames with overstrong beams connected together by relatively weak connections. This may explain much of the evidence from bomb damaged buildings in which building connections have been observed to fracture in a brittle manner when subjected to blast. The risk of progressive collapse may be minimized by strengthening beam to column connections located at close proximity to potential vehicle borne devices and a capacity design method for such strengthening is advocated.